JP6639221B2 - Drinking water dispenser - Google Patents

Description

  The present invention relates to a drinking water dispenser, and more particularly, to a drinking water dispenser that reliably removes various bacteria of drinking water to be sampled and does not cause taste transfer or odor.

  The drinking water dispenser (or drinking water server) is provided with a large-capacity bottle (about 7 to 12 L) filled with drinking water such as mineral water, and the necessary amount is timely collected in a cup or the like for drinking. Things. In recent years, the form in which this bottle is delivered to homes, restaurants, hospitals, various offices, and the like and consumed has increased.

  As such a conventional drinking water dispenser, for example, the one shown in FIG. According to the drinking water dispenser shown in the figure, the drinking water supplied from the bottle is cooled by a cooling mechanism provided in the drinking water dispenser and stored in a cold water tank, and is heated by a heating mechanism and heated water tank. It has a structure that is also stored. This allows the user to sample both cold and hot water.

  Since such a drinking water dispenser fills the bottle with drinking water containing no residual chlorine, when the bottle is replaced, when germs or the like adhere to the insertion port or the like and enter the inside of the dispenser, the mineral water is dispensed. There is a possibility that germs may occur in the inside. In particular, in a drinking water dispenser, in a flow path through which non-warm water such as cooling water or normal-temperature water flows, there is a possibility that germs invading from the outside may multiply.

  To solve such a problem, for example, Patent Literature 2 below discloses a method in which a filtration unit is provided in a passage upstream of a water outlet of drinking water. According to this method, the filter means removes various germs, so that the drinking water flowing out of the water outlet can be kept clean. Further, as the filtration means, a hollow fiber membrane and an adsorbent are disclosed, and it is said that when the hollow fiber membrane is used, extremely minute germs can be removed. It is said that it can adsorb chlorine, moldy odor and odor attached in a drinking water dispenser. Further, as the hollow fiber membrane, polyolefin-based hollow fiber membranes such as polyethylene and polypropylene are considered to be preferable from the viewpoint of handling properties and processing characteristics.

  However, depending on the type of the hollow fiber membrane to be used, there is a problem that the hollow fiber membrane is transferred to drinking water due to its resin origin and smells. As described above, by providing an adsorbent, it is said that the odor such as the residual chlorine can be adsorbed. However, since this adsorbent is installed on the upstream side of the hollow fiber membrane, the hollow fiber membrane is constituted. It is difficult to remove taste transfer and odor derived from the resin. It is also conceivable to install the adsorbent on the downstream side of the hollow fiber membrane, but in this case, since the adsorbent becomes a breeding ground for the propagation of various bacteria, there is a possibility that the bacteria invading from the water outlet may propagate on the adsorbent . As a result, there is a problem that various bacteria are detected from the sampled drinking water.

  In addition, it is conceivable to continue the passage of drinking water in order to remove the taste transfer and odor derived from the resin of the hollow fiber membrane, but it is necessary to conduct a large amount of water to completely remove the drinking water. In addition, a method of removing taste and odor by washing before installing the hollow fiber membrane in the drinking water dispenser may be considered. However, the pore size of the hollow fiber membrane changes due to the drying treatment after the washing, and the filtration performance is reduced. May decrease.

JP 2011-255960 A Republished patent WO2007 / 094364

  The present invention has been made in view of the above problems, and an object of the present invention is to remove germs and the like, and to prevent or reduce the transfer of taste and smell to drinking water to be collected. It is to provide a dispenser.

The above conventional problems are solved by the invention described below.
That is, the drinking water dispenser according to the present invention, in order to solve the above-described problems, a bottle that supplies drinking water, a main body that can be detachably installed with the bottle, and that discharges the drinking water from a water outlet. At least, the main body is provided with at least one hollow fiber membrane module for filtering the drinking water before water is discharged, the hollow fiber membrane in the hollow fiber membrane module has hydrophilicity, and It is characterized by being not graft polymerized.

  The graft polymerization is performed for the purpose of modifying the hollow fiber membrane to be hydrophilic when the hollow fiber membrane is inherently hydrophobic. However, if the hollow fiber membrane module modified by graft polymerization is used as a drinking water filtering means, it is presumed that the filtered drinking water has a taste shift and an odor. For this reason, in the present invention, as described above, the hollow fiber membrane module as the filtering means for drinking water has a configuration in which a hollow fiber membrane having hydrophilicity and not being subjected to graft polymerization is provided. This makes it possible to prevent the transfer of taste and smell while removing or reducing various bacteria of the drinking water after filtration.

  In the above configuration, the hollow fiber membrane is preferably a polysulfone-based hollow fiber membrane having hydrophilicity. The “polysulfone-based hollow fiber membrane” means a hollow fiber membrane using a polysulfone-based polymer as a main raw material.

  Further, in the above configuration, the main body is a storage tank for storing drinking water supplied from the bottle, and stores the drinking water at room temperature in the upper layer, and in the lower layer. A storage tank for cooling and storing, and a hot water tank positioned below the storage tank for storing drinking water supplied from the storage tank at a high temperature; connecting the water outlet and the storage tank to each other; A cooling water supply pipe for flowing the cooled drinking water stored in the tank, wherein the hollow fiber membrane module is provided at an arbitrary position of the cooling water supply pipe, and is provided from the storage tank. It is preferable that the supplied cooling water is filtered.

  Further, in the above configuration, the main body portion is another storage tank that stores drinking water supplied from the bottle at room temperature, and is located below the other storage tank and the other storage tank. A cooling water tank that cools and stores drinking water supplied from the storage tank, and a warm water tank that is located below the cooling water tank and stores drinking water supplied from the other storage tank at a high temperature, It is preferable that the thread membrane module is provided between the other storage tank and the cooling water tank, and filters the drinking water supplied from the other storage tank.

Further, in the above configuration, the main body portion is another storage tank that stores drinking water supplied from the bottle at room temperature, and is located below the other storage tank and the other storage tank. A cooling water tank that cools and stores drinking water supplied from the storage tank; a hot water tank that is located below the cooling water tank and stores drinking water supplied from the other storage tank at a high temperature; and the other storage drinking water at room temperature which is stored in a tank and a supply pipe for supplying the cooling water bath, the hollow fiber membrane module is disposed at an arbitrary position of the supply pipe, from said other reservoir It is preferable that the supplied normal-temperature drinking water be filtered.

  Further, in the above configuration, the main body includes an intake pipe for taking drinking water from the bottle, and the hollow fiber membrane module is provided at an arbitrary position of the intake pipe, It is preferable to filter drinking water taken from a bottle.

The present invention has the following effects by the means described above.
The drinking water dispenser of the present invention has a hydrophilic property and is provided with a hollow fiber membrane module that is not graft-polymerized. This has the effect of preventing the transfer of taste and odor derived from the graft-polymerized resin.

BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic diagram showing the whole structure of the drinking water dispenser which concerns on Embodiment 1 of this invention. It is a cross section showing the whole hollow fiber membrane module composition in the above-mentioned drinking water dispenser. It is a front view showing the whole structure of the drinking water dispenser. It is a cross section showing the whole composition of the drinking water dispenser concerning Embodiment 2 of the present invention. It is a cross section showing the whole composition of the drinking water dispenser concerning Embodiment 3 of the present invention. It is a cross section showing the whole composition of the drinking water dispenser concerning Embodiment 4 of the present invention. It is a schematic diagram showing the whole structure of the experimental device used by the Example and the comparative example.

(Embodiment 1)
The drinking water dispenser according to the present embodiment will be described below. FIG. 1 is a schematic cross-sectional view showing the entire configuration of the drinking water dispenser according to the first embodiment. FIG. 2 is a schematic cross-sectional view illustrating an entire configuration of a hollow fiber membrane module in the drinking water dispenser. FIG. 3 is a front view illustrating an entire configuration of the drinking water dispenser.

  As shown in FIG. 1, a drinking water dispenser 10 of the present embodiment includes at least a bottle 11 for supplying drinking water 15 and a main body 12 to which the bottle 11 can be detachably mounted. Configuration.

  The main body 12 includes a water outlet 13 for discharging drinking water 15, a storage tank 14 for storing drinking water supplied from the bottle 11, a hot water tank 16 provided below the storage tank 14, and a water outlet 13. It mainly includes a cooling water supply pipe 17 connecting the tank 14 and a hollow fiber membrane module 18 provided in the cooling water supply pipe 17.

  The bottle 11 is attached to the water inlet 19 in the upper part of the main body 12 with the water inlet 36 facing downward. At the center of the water inlet receiver 19, an intake pipe 20 for inserting the drinking water 15 into the water inlet 36 of the bottle 11 is provided upright. The drinking water 15 taken in by the water intake pipe 20 is stored in the storage tank 14. The constituent material of the bottle 11 is not particularly limited, and examples thereof include PET (polyethylene terephthalate).

  The storage tank 14 stores the drinking water 15 supplied from the bottle 11 by dividing the drinking water 15 into normal-temperature drinking water and cooling water cooled to a certain temperature. More specifically, a plate-shaped separator 21 is provided inside the storage tank 14, a room-temperature water layer 14 a for storing drinking water at room temperature is provided above the separator 21, and a room-temperature water layer 14 a is provided below the separator 21. A cooling water layer 14b for cooling and storing the drinking water is provided. Cooling means (not shown) is provided at a portion corresponding to the lower side of the separator 21 on the outer periphery of the storage tank 14, thereby cooling the drinking water stored in the cooling water layer 14 b. it can.

  A cooling water supply pipe 17 communicating with the water outlet 13 is connected to the storage tank 14. Since the cooling water supply pipe 17 is connected to the bottom of the storage tank 14, only the cooling water in the cooling water layer 14b in the storage tank 14 flows through the cooling water supply pipe 17.

  An external communication section 34 having a built-in filter is provided on the ceiling of the storage tank 14. When the normal temperature drinking water or cooling water is taken out from the storage tank 14, or when the hot water is taken out from the hot water tank 16, the outside air is taken in from the external communication part 34 to prevent the pressure in the storage tank 14 from decreasing. can do. As a result, the water level of the drinking water stored in the normal temperature water layer 14a can be reduced without difficulty. Further, when the drinking water 15 is supplied from the bottle 11 to the storage tank 14, the pressure in the storage tank 14 is increased by discharging the air inside the storage tank 14 through the external communication part 34. Can be suppressed. Thereby, drinking water can be stored in the storage tank 14 without difficulty. Since the external communication portion 34 is provided with the filter, it is possible to prevent invasion of various bacteria and the like into the storage tank 14.

  The cooling water supply pipe 17 is provided with a hollow fiber membrane module 18. Here, as shown in FIG. 2, the hollow fiber membrane module 18 has a structure in which a filter medium including the hollow fiber membrane 22 fixed in a liquid-tight manner by a sealing material 23 is provided inside a main case 26. The hollow fiber membrane 22 is bent on the upstream side (primary side), and is provided such that both ends are fixed by the sealing material 23 on the downstream side (secondary side).

  Cooling water as raw water flowing from the storage tank 14 through the cooling water supply pipe 17 flows into the hollow fiber membrane module 18 from the cooling water inlet 24, is filtered by the hollow fiber membrane 22, and is filtered as filtered water from the filtered water outlet 25. Run out. This makes it possible to remove various bacteria of the cooling water. When the flow direction of the raw water is reversed, that is, in the direction from the secondary side to the primary side, the pressure loss becomes too large and almost no flow occurs.

  The hollow fiber membrane 22 is porous and has a tubular structure. The hollow fiber membrane 22 is not particularly limited as long as it has hydrophilicity and has not been subjected to graft polymerization. Examples of such a hollow fiber membrane 22 include a hollow fiber membrane whose properties are inherently hydrophilic and a hollow fiber membrane imparted with hydrophilicity. Examples of the hollow fiber membrane whose intrinsic properties are hydrophilic include, for example, those made of various materials such as cellulose, polyvinyl alcohol, ethylene / vinyl alcohol copolymer, polyacrylonitrile, and polyamide. . Examples of the hollow fiber membrane provided with the hydrophilicity include polyolefin (polyethylene, polypropylene), polyether, polymethyl methacrylate, polysulfone, polytetrafluoroethylene, polyvinylidene fluoride, and the like. It is made of various materials such as polycarbonate, polyester, etc., and has surface treatments such as coating, ozone, plasma, ultraviolet (UV), electron beam (EB), chemical etching, metal oxide deposition or sputtering. That have been given. In addition, a blend obtained by adding a hydrophilic polymer to these various materials may be used.

  Examples of the polysulfone-based polymer include polysulfone, polyethersulfone, and polyphenylenesulfone.

  The method for hydrophilizing the polysulfone-based hollow fiber membrane is not particularly limited, and a conventionally known method can be employed. Specifically, for example, a method of imparting hydrophilicity to a polysulfone-based hollow fiber membrane by adding an appropriate amount of a hydrophilic polymer such as polyvinylpyrrolidone is exemplified.

Effective membrane area is preferably 0.1 m ² or more hollow fiber membrane ^22, and more preferably 0.1 m 2 0.5 m ^2. By setting the effective membrane area to 0.1 m ² or more, it is possible to maintain the filtration performance of various bacteria and the like, and to prevent the filtration life from becoming excessively short. On the other hand, the upper limit of the effective membrane area is not particularly limited because the larger the effective membrane area is, the longer the filtration life is. However, when the effective membrane area exceeds 0.5 m ² , the filtration performance is saturated, and the improvement of the filtration effect cannot be expected much.

  The pore size of the hollow fiber membrane 22 is preferably 0.01 μm to 0.45 μm, and more preferably 0.01 μm to 0.1 μm. By setting the pore diameter to 0.01 μm or more, it is possible to suppress clogging and pressure loss from increasing, and to prevent the flow from becoming difficult. On the other hand, by setting the pore diameter to 0.45 μm or less, it becomes possible to remove germs and the like.

  The outer diameter of the hollow fiber membrane 22 is not particularly limited, and can be appropriately set as needed. Usually, it is 20 μm to 3000 μm. Further, the thickness of the hollow fiber membrane 22 is not particularly limited, and can be appropriately set as needed. Usually, it is 5 μm to 1000 μm. Further, the filling rate of the hollow fiber membrane 22 into the main case 26 is preferably 30% to 50%. By setting the filling rate to 30% or more, a decrease in filtration performance can be suppressed. On the other hand, by setting the filling rate to 50% or less, it is possible to prevent the production from becoming difficult in the production process.

  The sealing material 23 is not particularly limited, and a conventionally known material made of a urethane resin, an epoxy resin, a polyolefin resin, or the like can be used.

  Further, a pump 27 is provided in the cooling water supply pipe 17 on the upstream side of the hollow fiber membrane module 18. Thus, the cooling water can be pumped at a flow rate equal to or higher than a certain value. However, the present embodiment is not limited to this mode, and cooling water can be collected even if the pump 27 is omitted. Further, the pump 27 may be provided on the downstream side of the hollow fiber membrane module 18.

  Further, the cooling water supply pipe 17 is connected to the cold water outlet 13a, whereby the germs are removed or reduced by the hollow fiber membrane module 28, and the cooling water whose taste transfer and odor are suppressed can be discharged. (See FIG. 3).

  The hot water tank 16 is located below the storage tank 14. The hot water tank 16 is provided with a heater (not shown) for heating the stored drinking water, and is stored in a hot water state. The hot water tank 16 is provided with a supply pipe 29 for enabling normal temperature drinking water to be supplied from the normal temperature water layer 14a in the storage tank 14. An inlet opening 29 a of the supply pipe 29 is open to the room-temperature water layer 14 a of the storage tank 14. Further, the outlet opening 29b is open on the bottom side of the hot water tank 16. Further, the hot water tank 16 is connected to the hot water outlet 13b via a hot water supply pipe 28, whereby hot water can be discharged from the hot water outlet 13b (see FIG. 3).

  In addition, the drinking water dispenser 10 of the present embodiment suppresses the transfer of taste and smell to drinking water by merely installing the hollow fiber membrane module 18 immediately before the upstream side of the water outlet 13. Thus, it is possible to remove or reduce various bacteria. Therefore, it is possible to avoid a complicated device configuration.

(Embodiment 2)
The drinking water dispenser according to the second embodiment will be described below with reference to FIG. FIG. 4 is a schematic cross-sectional view illustrating the entire configuration of the drinking water dispenser according to the second embodiment. The components having the same functions as those of the drinking water dispenser according to the first embodiment are denoted by the same reference numerals, and detailed description is omitted.

  As shown in FIG. 4, the drinking water dispenser 30 of the present embodiment is different from the drinking water dispenser 10 of the first embodiment in that normal-temperature drinking water and cooling water are separately stored in separate tanks. The difference is that the hollow fiber membrane module 18 is arranged so as to communicate between them. Another difference is that an exhaust pipe 35 is provided to alleviate the pressure fluctuation inside the cooling water tank 33.

  More specifically, the drinking water dispenser 30 includes, in the main body portion 31, another storage tank 32, a cooling water tank 33 located below the other storage tank 32, and a temperature tank located below the cooling water tank 33. A water tank 16 is mainly provided.

  The other storage tank 32 stores drinking water supplied from the bottle 11 at normal temperature. The cooling water tank 33 cools the normal-temperature drinking water supplied from another storage tank 32 via the hollow fiber membrane module 18 and stores it as cooling water. Further, by providing the external communication portion 34 provided on the ceiling of the other storage tank 32, it becomes possible to take in external air through the external communication portion 34. As a result, it is possible to prevent the inside of the bottle 11 from becoming negative pressure and the supply amount of the drinking water 15 from the bottle 11 to the other storage tank 32 from being reduced.

  The cooling water stored in the cooling water tank 33 is filtered by the hollow fiber membrane module 18 to remove or reduce various bacteria. As described above, since the hollow fiber membrane module 18 includes the hollow fiber membrane 22 that has hydrophilicity and is not graft-polymerized, the cooling water is prevented from being transferred and smelled. can do.

  The cooling water supply pipe 17 for communicating with the water outlet 13 is connected to the bottom of the cooling water tank 33. The cooling water supply pipe 17 is provided with a pump 27, which enables the cooling water flowing through the cooling water supply pipe 17 to have a certain flow rate or more. However, the present embodiment is not limited to this mode, and water can be collected without installing the pump 27.

  The exhaust pipe 35 connects the top of the cooling water tank 33 and the top of the storage tank 32. The drainage pipe 35 reduces the pressure fluctuation when the water pressure inside the cooling water tank 33 rises and the pressure rises. The lower side of the exhaust pressure pipe 35 is filled with cooling water, and when the internal pressure of the cooling water tank 33 is not particularly high, the water level of the cooling water is the same as the water level of the storage tank 32. The upper side of the exhaust pipe 35 is filled with air. Then, when the drinking water stored in another storage tank 32 is filtered by the hollow fiber membrane module 18 and the cooling water newly stored in the cooling water tank 33 increases, the internal pressure in the cooling water tank 33 increases. . At this time, in the exhaust pressure pipe 35, the level of the cooling water filled on the lower side rises by the internal pressure raised in the cooling water tank 33, and the upper air is discharged to the air layer 43 of the other storage tank 32. . Further, in the other storage tank 32, since air can be discharged to the outside via the external communication portion 34, it is possible to prevent the pressure inside the other storage tank 32 from increasing. Can be. As a result, the exhaust pressure pipe 35 can reduce pressure fluctuations in the cooling water tank 33.

  Further, the hot water tank 16 is provided with a supply pipe 29 for enabling normal-temperature drinking water to be supplied from another storage tank 32. The supply pipe 29 has an inlet opening 29 a opened to the other storage tank 32 and an outlet opening 29 b opened to the bottom side of the hot water tank 16.

(Embodiment 3)
The drinking water dispenser according to the third embodiment will be described below with reference to FIG. FIG. 5 is a schematic cross-sectional view illustrating an entire configuration of a drinking water dispenser according to Embodiment 3. Note that components having the same functions as those of the drinking water dispensers according to the first and second embodiments are denoted by the same reference numerals, and detailed description is omitted.

  As shown in FIG. 5, the drinking water dispenser 40 of the present embodiment connects the other storage tank 32 and the cooling water tank 33 with a supply pipe 42, as compared with the drinking water dispenser 30 of the second embodiment. The difference is that the hollow fiber membrane module 18 is provided in the supply pipe 42.

  The supply pipe 42 is provided with an inlet opening 42a in an aqueous layer portion of the other storage tank 32 in which normal-temperature drinking water is stored. The hollow fiber membrane module 18 can be provided at an arbitrary position of the supply pipe 42. Thereby, the cooling water stored in the cooling water tank 33 is filtered in advance by the hollow fiber membrane module 18 to remove or reduce various bacteria. Further, as described above, the hollow fiber membrane module 18 has the hollow fiber membrane 22 which has hydrophilicity and is not graft-polymerized, so that the transfer of drinking water to the flavor and odor is prevented. are doing.

  In addition, the cooling water supply pipe 17 is provided with a pump 27, whereby the cooling water can be pumped at a fixed flow rate or more. However, the present embodiment is not limited to this mode, and the cooling water can be collected without installing the pump 27. Further, the pump 27 may be provided in the supply pipe 42. In this case, the pump 27 may be provided on either the upstream side or the downstream side of the hollow fiber membrane module 18.

(Embodiment 4)
The drinking water dispenser according to the fourth embodiment will be described below. FIG. 6 is a schematic cross-sectional view illustrating an entire configuration of a drinking water dispenser according to the fourth embodiment. Note that components having the same functions as those of the drinking water dispensers of the first to third embodiments are denoted by the same reference numerals, and detailed description thereof will be omitted.

  As shown in FIG. 6, the drinking water dispenser 50 of the present embodiment is different from the drinking water dispenser 10 of the first embodiment in that the hollow fiber membrane module 18 is provided in the water intake pipe 20.

  In the present embodiment, the hollow fiber membrane module 18 can be provided at an arbitrary position of the water intake pipe 20. Thereby, the drinking water stored in the normal temperature water layer 14a, the cooling water stored in the cooling water tank 33, and the hot water stored in the hot water tank 16 are filtered in advance by the hollow fiber membrane module 18 to remove or reduce germs. Can be done. Further, as described above, the hollow fiber membrane module 18 has the hydrophilic fiber and the hollow fiber membrane 22 that has not been subjected to graft polymerization. Preventing.

  In the present embodiment, the case where the hollow fiber membrane module 18 provided in the cooling water supply pipe 17 is provided in the water intake pipe 20 in the drinking water dispenser 10 of the first embodiment has been described. However, the present invention is not limited to this. For example, the present invention is also applicable to the drinking water dispenser 30 of the second embodiment and the drinking water dispenser 40 of the third embodiment by providing the hollow fiber membrane module 18 in each intake pipe 20.

  Hereinafter, preferred embodiments of the present invention will be illustratively described in detail. However, the materials and the like described in the following examples do not limit the scope of the present invention only to them unless otherwise limited.

(Example 1)
In the present example, the mineral water (trade name; AW Water, natural water of the Northern Alps, manufactured by Air Water Co., Ltd.) filled in the bottle 11 was filtered using the experimental apparatus shown in FIG. . That is, a bottle 11 filled with mineral water and a container 51 for receiving filtered water obtained by filtering the bottle were connected by a supply pipe 52, and a hollow fiber membrane module 50 was provided in the supply pipe 52. Further, a pump 27 was also installed on the upstream side of the hollow fiber membrane module 50. Further, as the hollow fiber membrane module 50, a polysulfone-based hollow fiber membrane module (model number: AWPSF01, manufactured by KITZ Micro Filter Co., Ltd.) having the shape, effective membrane area, and pore diameter shown in Table 1 below was used.

  Filtration using the hollow fiber membrane module 50 was performed as follows. That is, using the pump 27, the normal temperature (20 to 25 ° C.) mineral water stored in the bottle 11 was pumped, filtered through the hollow fiber membrane module 50, and the first 200 ml of filtered water was collected.

  Next, TOC (Total Organic Carbon) concentration analysis was performed on the collected filtered water, and the organic components eluted from the hollow fiber membrane module 50 were confirmed.

  Specifically, first, 2.125 g of potassium hydrogen phthalate was dissolved in purified water to prepare a 1 L phthalic acid solution, which was used as a total organic carbon standard stock solution (1 ml of this solution contains 1 mg of carbon). Further, the phthalic acid solution as the total organic carbon standard stock solution was further diluted 100 times with purified water, and the obtained phthalic acid solution was used as the total organic carbon standard solution (1 ml of this solution was 0.01 mg of carbon). including).

  Next, the total organic carbon standard solution was taken stepwise into four or more volumetric flasks, and purified water was added to each to make a fixed amount. Further, a correction corresponding to a calibration curve was performed according to the correction method of the following apparatus.

  A fixed amount of the filtered water and raw water before the filtration were measured with a total organic carbon determination device (model number: TOC-VCSH, manufactured by Shimadzu Corporation), and the concentration of the total organic carbon in the test water was calculated. The results are shown in Table 2 below.

  A sensory test was also performed on the filtered water sampled as described above. The sensory test was performed to determine whether or not the filtered water had a taste change or odor derived from the resin of the hollow fiber membrane module 50.

  That is, 21 males and females aged 20s to 50s were allowed to taste the sampled filtered water at normal temperature to evaluate whether or not the taste and smell were uncomfortable. The results are shown in Table 3 below.

(Comparative Example 1)
In this comparative example, a polyethylene-based hollow fiber membrane module having the shape, effective membrane area, and pore diameter shown in Table 1 below was used as the hollow fiber membrane module 50. As the constituent material of the hollow fiber membrane, polyethylene represented by the following chemical formula, which was made hydrophilic by graft polymerization, was used. Otherwise, the mineral water filled in the bottle 11 was filtered in the same manner as in Example 1.

  Further, a TOC concentration analysis and a sensory test were also performed in the same manner as in Example 1. The results are shown in Tables 2 and 3 below. However, in the sensory test, the test was performed on 20 men and women in their 20s to 50s.

(result)
As can be seen from Table 2, the polyethylene-based hollow fiber membrane module of Comparative Example 1 had a TOC concentration of 2.26 mg / L, whereas the polysulfone-based hollow fiber membrane module of Example 1 had a TOC concentration of 0.2. It was 63 mg / L, and it was confirmed that elution of the organic component was suppressed.

  As can be seen from Table 3, in the polysulfone-based hollow fiber membrane module of Example 1, the number of panelists who had an uncomfortable taste was 4/21, and in the polyethylene-based hollow fiber membrane module of Comparative Example 1, 20 Nineteen of the people answered that the taste was uncomfortable. The result was subjected to a significant difference test (calculated by Fisher's exact probability method using Statcel3 software (manufactured by OSM Publishing Co.)), and the p value was p <0.001, and Example 1 It can be said that the result of Comparative Example 1 has a statistically significant difference.

  From this fact, the mineral water (filtration water) passed through the polysulfone-based hollow fiber membrane module that has not been subjected to the grafting process has a taste and smell that is lower than that of the mineral water passed through the polyethylene-based hollow fiber membrane module. It was confirmed that the organic components estimated to be the source were small.

10, 30, 40, 50 Drinking water dispenser 11 Bottle 12, 31 Main body 13 Water outlet 14 Storage tank 14a Room temperature water layer 14b Cooling water layer 15 Drinking water 16 Hot water tank 17 Cooling water supply pipe 18, 28, 50 Hollow fiber membrane Module 19 Injection port receiver 20 Intake pipe 21 Separator 22 Hollow fiber membrane 23 Sealing material 24 Cooling water inlet 25 Filtered water outlet 26 Main case 27 Pump 28 Hot water supply pipe 29 Supply pipe 29a Inlet opening 29b Outlet opening 32 Storage tank 33 Cooling water tank 34 external communication part 35 drainage pipe 36 water inlet 42 supply pipe 42a inlet opening 43 air layer 51 container 52 supply pipe

Claims (7)

A bottle that supplies drinking water,
The bottle can be installed detachably, and at least a main body for discharging the drinking water from a water outlet,
The main body is provided with at least one hollow fiber membrane module for filtering the drinking water before water is discharged,
The drinking water dispenser, wherein the hollow fiber membrane in the hollow fiber membrane module has hydrophilicity and is not graft-polymerized.   The drinking water dispenser according to claim 1, wherein the hollow fiber membrane is a polysulfone-based hollow fiber membrane having hydrophilicity. The main body is
A storage tank for storing drinking water supplied from the bottle, and stores the drinking water at room temperature in the upper layer, and cools and stores in the lower layer,
A hot water tank that is located below the storage tank and stores drinking water supplied from the storage tank at a high temperature,
A connection between the water outlet and the storage tank, and a cooling water supply pipe for flowing cooled drinking water stored in the storage tank,
The drinking water dispenser according to claim 1, wherein the hollow fiber membrane module is provided at an arbitrary position of the cooling water supply pipe, and filters the cooling water supplied from the storage tank. The main body is
Another storage tank that stores drinking water supplied from the bottle at room temperature,
A cooling water tank that is located below the other storage tank and cools and stores drinking water supplied from the other storage tank,
A hot water tank that is located below the cooling water tank and stores drinking water supplied from the other storage tank at a high temperature,
The drinking water according to claim 1, wherein the hollow fiber membrane module is provided between the other storage tank and the cooling water tank, and filters the drinking water supplied from the other storage tank. Dispenser. The main body is
Another storage tank that stores drinking water supplied from the bottle at room temperature,
A cooling water tank that is located below the other storage tank and cools and stores drinking water supplied from the other storage tank,
A hot water tank that is located below the cooling water tank and stores drinking water supplied from the other storage tank at a high temperature,
Drinking water at room temperature that is stored in the other storage tank and a supply pipe for supplying the cooling water tank,
The drinking water dispenser according to claim 1, wherein the hollow fiber membrane module is provided at an arbitrary position of the supply pipe and filters room temperature drinking water supplied from the other storage tank. . The main body is
An intake pipe for taking drinking water from the bottle,
The drinking water dispenser according to claim 1, wherein the hollow fiber membrane module is provided at an arbitrary position of the water intake pipe, and filters drinking water taken from the bottle.   The drinking water dispenser according to claim 2, wherein the polysulfone-based hollow fiber membrane is made of polysulfone, polyether sulfone, or polyphenylene sulfone.

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